It is well known that many people snore when asleep. Snoring is an unconscious activity which is often not even noticed by the person who snores, but is typically quite bothersome to those sleeping nearby.
Medical references define snoring as a rough, rattling, inspiratory noise generally produced by vibration of the pendulous palate, or sometimes by the vocal cords, during sleep. Snoring may be produced as a rale, especially a whistling or sonorous rale produced in the larger bronchi or the trachea. This condition is caused by some narrowing of the upper airway passages, such that when the person is asleep, the airflow is somewhat obstructed and must be forced.